Effect of Combustion Bowl Shape on Performance Combustion and Emission Characteristics of Diesel Engine Using Biodiesel with TiO ₂ Nanoparticle Additive as Fuel

The purpose of this experimental investigation is to determine the optimized geometry for the combustion bowl of invariant speed compression ignition engine operated with biodiesel. The sesame biodiesel has been considered for the current proposed work. To enhance the performance characteristics and reduce the emission magnitudes, the sesame methyl ester of 20% blended with diesel fuel of 80% (S20-D80).The nanoparticle additive of titanium oxide at the rate 0f 25 ppm was added to the blend (S20-D80+ 25 ppm). Furthermore improvement in performance of the engine, two diverse combustion bowls was designed with respect to various literature studies. Toroidal U- shape combustion bowl (MP-i) and Toroidal Stepped V-shape combustion bowl (MP-ii) were selected for the current study. The engine performance, combustion and emissions has been analyzedon both modified piston bowl and compared with the standard piston. The findings of the experimental investigations have been deliberated for the engine operating conditions by varying the load from zero to maximum for improved understanding. S20-D80 + 25 ppm showed enhanced characteristics of engine due to collective effect of the oxygen elements demeanor fuel and loftier thermal stability and also the instigation energy of the titanium oxide (TiO₂) nanoparticle additive. From the two piston bowl modifications, Modified piston bowl-I (MP-i) exhibited superior engine characteristics as that of Modified piston bowl -II (MP- ii) and standard piston bowl. The MP-I exhibited greater BTE and inferior BSFC of 4.5% and 12.5% particularly at engine operated with low and full load for S20-D80 + 25 ppm blend. Emission magnitude of HC, CO and smoke opacity was reduced at full load condition but marginally increased in oxides of nitrogen and carbon. It was clinched that combustion bowl of Toroidal U-shape (MP-i) found to be optimized one for S20-D80 + 25 ppm Titanium oxide additive nanoparticle.